Zeolite SSZ-24

ABSTRACT

A crystalline zeolite SSZ-24 is prepared using an adamantane quaternary ion as a template.

This is a continuation-in-part of Ser. No. 823,704, filed Jan. 29, 1986now abandoned.

BACKGROUND OF THE INVENTION

Natural and synthetic zeolitic crystalline aluminosilicates are usefulas catalysts and adsorbents. These aluminosilicates have distinctcrystal structures which are demonstrated by X-ray diffraction. Thecrystal structure defines cavities and pores which are characteristic ofthe different species. The adsorptive and catalytic properties of eachcrystalline aluminosilicate are determined in part by the dimensions ofits pores and cavities. Thus, the utility of a particular zeolite in aparticular application depends at least partly on its crystal structure.

Because of their unique molecular sieving characteristics, as well astheir catalytic properties, crystalline aluminosilicates are especiallyuseful in such applications as gas drying and separation and hydrocarbonconversion. Although many different crystalline aluminosilicates andsilicates have been disclosed, there is a continuing need for newzeolites and silicates with desirable properties for gas separation anddrying, hydrocarbon and chemical conversions, and other applications.

Crystalline aluminosilicates are usually prepared from aqueous reactionmixtures containing alkali or alkaline earth metal oxides, silica, andalumina. "Nitrogenous zeolites" have been prepared from reactionmixtures containing an organic templating agent, usually anitrogen-containing organic cation. By varying the synthesis conditionsand the composition of the reaction mixture, different zeolites can beformed using the same templating agent. Use of N,N,N-trimethylcyclopentylammonium iodide in the preparation of Zeolite SSZ-15molecular sieve is disclosed in my copending application Ser. No.437,709, filed on Oct. 29, 1982 now U.S. Pat. No. 4,610,854; use of1-azoniaspiro [4.4] nonyl bromide and N,N,N-trimethyl neopentylammoniumiodide in the preparation of a molecular sieve termed "Losod" isdisclosed in Helv. Chim. Acta (1974); Vol. 57, page 1533 (W. Sieber andW. M. Meier); use of quinuclidinium compounds to prepare a zeolitetermed "NU-3" is disclosed in European Patent Publication No. 40016; useof 1,4-di(1-azoniabicyclo [2.2.2.]octane) lower alkyl compounds in thepreparation of Zeolite SSZ-16 molecular sieve is disclosed in U.S. Pat.No. 4,508,837; use of N,N,N-trialkyl-1-adamantamine in the preparationof zeolite SSZ-13 molecular sieve is disclosed in U.S. Pat. No.4,544,538.

SUMMARY OF THE INVENTION

I have prepared a family of crystalline aluminosilicate molecular sieveswith unique properties, referred to herein as "Zeolite SSZ-24", orsimply "SSZ-24", and have found a highly effective methode for preparingSSZ-24.

SSZ-24 has a mole ratio of an oxide selected from silicon oxide,germanium oxide, and mixtures thereof to an oxide selected from aluminumoxide, gallium oxide, iron oxide, boron oxide and mixtures thereofgreater than about 100:1 and having the X-ray diffraction lines of Table1 below. The zeolite further has a composition, as synthesized and inthe anhydrous state, in terms of mole ratios of oxides as follows: (0.1to 10)(Q₂ O:(0.1 to 5.0)M₂ O:W₂ O₃ :(greater than 100)YO₂ wherein M isan alkali metal cation, W is selected from aluminum, gallium, iron,boron and mixtures thereof, Y is selected from silicon, germanium andmixtures thereof, and Q is an adamantane quaternary ammonium ion. SSZ-24zeolites can have a YO₂ :W₂ O₃ mole ratio greater than about 100:1 andcan be made essentially alumina free. As prepared, the silica:aluminamole ratio is typically in the range of 100:1 to about 10,000:1. Highermole ratios can be obtained by treating the zeolite with chelatingagents or acids to extract aluminum from the zeolite lattice. Thesilica:alumina mole ratio can also be increased by using silicon andcarbon halides and other similar compounds. Preferably, SSZ-24 is analuminosilicate wherein W is aluminum and Y is silicon.

Lower ratios of silica to alumina may also be obtained by using methodswhich insert alumina into the crystalline network. For example, aluminainsertion may occur by thermal treatment of the zeolite in combinationwith an alumina binder or dissolved source of alumina. Such proceduresare described in the prior art, e.g., U.S. Pat. Nos. 4,599,315 and4,550,092.

By "essentially alumina-free" as used herein, refers to silicaceouscrystalline molecular sieves wherein any alumina is present as animpurity in the starting materials but for the impurity would not bepresent in the silicate.

My invention also involves a method for preparing SSZ-24 zeolites,comprising preparing an aqueous mixture containing sources of anadamantane quaternary ammonium ion, an oxide selected from aluminumoxide, gallium oxide, iron oxide, boron oxide and mixtures thereof, andan oxide selected from silicon oxide, germanium oxide, and mixturesthereof, and having a composition, in terms of mole ratios of oxides,falling within the following ranges: YO₂ /W₂ O₃, 100:1 to infinity(essentially pure YO₂); wherein Y is selected from silicon, germanium,and mixtures thereof, W is selected from aluminum, gallium, iron, boronand mixtures thereof, and Q is an adamantane quaternary ammonium ion;maintaining the mixture at a temperature of at least 100° C. until thecrystals of said zeolite are formed; and recovering said crystals.

DETAILED DESCRIPTION OF THE INVENTION

SSZ-24 zeolites, as synthesized, have a crystalline structure whoseX-ray powder diffraction pattern shows the following characteristiclines:

                  TABLE 1                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        7.50           11.79   98                                                     13.00          6.89    10                                                     15.00          5.91    46                                                     19.91          4.46    100                                                    21.42          4.15    36                                                     22.64          3.93    87                                                     26.16          3.41    44                                                     29.37          3.04    13                                                     30.31          2.949   30                                                     34.86          2.574   20                                                     38.29          2.351    7                                                     ______________________________________                                    

Typical SSZ-24 aluminosilicate zeolites have the X-ray diffractionpattern of Tables 2 and 4 below.

The X-ray powder diffraction patterns were determined by standardtechniques. The radiation was the K-alpha/doublet of copper and ascintillation counter spectrometer with a strip-chart pen recorder wasused. The peak heights I and the positions, as a function of 2θ where θis the Bragg angle, were read from the spectrometer chart. From thesemeasured values, the relative intensities, 100I/I₀, where I₀ is theintensity of the strongest line or peak, and d, the interplanar spacingin Angstroms corresponding to the recorded lines, can be calculated. TheX-ray diffraction pattern of Table 1 is characteristic of SSZ-24zeolites. The zeolite produced by exchanging the metal or other cationspresent in the zeolite with various other cations yields substantiallythe same diffraction pattern although there can be minor shifts ininterplanar spacing and minor variations in relative intensity. Minorvariations in the diffraction pattern can also result from variations inthe organic compound used in the preparation and from variations in thesilica-to-alumina mole ratio from sample to sample. Calcination can alsocause minor shifts in the X-ray diffraction pattern. Notwithstandingthese minor perturbations, the basic crystal lattice structure remainsunchanged.

SSZ-24 zeolites can be suitably prepared from an aqueous solutioncontaining sources of an alkali metal oxide, an adamantane quaternaryammonium ion, an oxide of aluminum, gallium, iron, boron or mixturesthereof, and an oxide of silicon or germanium, or mixture of the two.The reaction mixture should have a composition in terms of mole ratiosfalling within the following ranges:

    ______________________________________                                                      Broad  Preferred                                                ______________________________________                                        YO.sub.2 /W.sub.2 O.sub.3                                                                     50-∞                                                    OH.sup.- /YO.sub.2                                                                            0.10-1.0 0.20-0.30                                            Q/YO.sub.2      0.05-0.50                                                                              0.10-0.20                                            M.sup.+ /YO.sub.2                                                                             0.05-0.30                                                                              0.05-0.15                                            H.sub.2 O/YO.sub.2                                                                             20-300  35-60                                                Q/Q + M.sup.+   0.30-0.70                                                                              0.40-0.60                                            ______________________________________                                    

wherein Q is an adamantane quaternary ammonium ion, Y is silicon,germanium or both, and W is aluminum, gallium, iron, boron or mixturesthereof. M is an alkali metal, preferably sodium or potassium. Theorganic adamantane compound which acts as a source of the adamantanequaternary ammonium ion employed can provide hydroxide ion.

When using the adamantane quaternary ammonium hydroxide compound as atemplate, it has also been found that purer forms of SSZ-24 are preparedwhen there is an excess of adamantane compound present relative to theamount of alkali metal hydroxide and that when the OH⁻ /SiO₂ molar ratiois greater than 0.40, then M⁺ /SiO₂ molar ratio should be less than0.02.

The adamantane quaternary ammonium ion component Q, of thecrystallization mixture, is derived from an adamantane quaternaryammonium compound. Preferably, the adamantane quaternary ammonium ion isderived from a compound of the formula ##STR1## wherein each of Y₁ Y₂and Y₃ independently is lower alkyl and most preferably methyl; A.sup.⊖is an anion which is not detrimental to the formation of the zeolite;and each of R₁, R₂, and R₃ independently is hydrogen, or lower alkyl andmost preferably hydrogen; and ##STR2## wherein each of R₄, R₅ and R₆independently is hydrogen or lower alkyl; and most preferably hydrogen;each of Y₁, Y₂ and Y₃ independently is lower alkyl and most preferablymethyl; and A.sup.⊖ is an anion which is not detrimental to theformation of the zeolite;

The adamantane quaternary ammonium compounds are prepared by methodsknown in the art.

By "lower alkyl" is meant alkyl of from about 1 to 5 carbon atoms.

A.sup.⊖ is an anion which is not detrimental to the formation of thezeolite. Representative of the anions include halogen, e.g., fluoride,chloride, bromide and iodide, hydroxide, acetate, sulfate, carboxylate,etc. Hydroxide is the most preferred anion. It may be beneficial toion-exchange, for example, the halide for hydroxide ion, therebyreducing or eliminating the alkali metal hydroxide quantity required.

The reaction mixture is prepared using standard zeolitic preparationtechniques. Typical sources of aluminum oxide for the reaction mixtureinclude aluminates, alumina, and aluminum compounds such as AlCl₃ andAl₂ (SO₄)₃. Typical sources of silicon oxide include silicates, silicahydrogel, silicic acid, colloidal silica, tetraalkyl orthosilicates, andsilica hydroxides. Gallium, iron, boron and germanium can be added informs corresponding to their aluminum and silicon counterparts. Salts,particularly alkali metal halides such as sodium chloride, can be addedto or formed in the reaction mixture. They are disclosed in theliterature as aiding the crystallization of zeolites while preventingsilica occlusion in the lattice.

The reaction mixture is maintained at an elevated temperature until thecrystals of the zeolite are formed. The temperatures during thehydrothermal crystallization step are typically maintained from about140° C. to about 200° C., preferably from about 150° C. to about 170° C.and most preferably from about 135° C. to about 165° C. Thecrystallization period is typically greater than 1 day and preferablyfrom about 3 days to about 7 days.

The hydrothermal crystallization is conducted under pressure and usuallyin an autoclave so that the reaction mixture is subject to autogenouspressure. The reaction mixture can be stirred during crystallization.

Once the zeolite crystals have formed, the solid product is separatedfrom the reaction mixture by standard mechanical separation techniquessuch as filtration. The crystals are water-washed and then dried, e.g.,at 90° C. to 150° C. for from 8 to 24 hours, to obtain the assynthesized, SSZ-24 zeolite crystals. The drying step can be performedat atmospheric or subatmospheric pressures.

During the hydrothermal crystallization step, the SSZ-24 crystals can beallowed to nucleate spontaneously from the reaction mixture. Thereaction mixture can also be seeded with SSZ-24 crystals both to direct,and accelerate the crystallization, as well as to minimize the formationof undesired aluminosilicate contaminants. If the reaction mixture isseeded with SSZ-24 crystals, the concentration of the organic compoundcan be greatly reduced or eliminated, but it is preferred to have someorganic compound present, e.g., an alcohol.

The synthetic SSZ-24 zeolites can be used as synthesized or can bethermally treated (calcined). Usually, it is desirable to remove thealkali metal cation by ion exchange and replace it with hydrogen,ammonium, or any desired metal ion. The zeolite can be leached withchelating agents, e.g., EDTA or dilute acid solutions, to increase thesilica:alumina mole ratio. The zeolite can also be steamed; steaminghelps stabilize the crystalline lattice to attack from acids. Thezeolite can be used in intimate combination with hydrogenatingcomponents, such as tungsten, vanadium, molybdenum, rhenium, nickel,cobalt, chromium, manganese, or a noble metal, such as palladium orplatinum, for those applications in which ahydrogenation-dehydrogenation function is desired. Typical replacingcations can include metal cations, e.g., rare earth, Group IIA and GroupVIII metals, as well as their mixtures. Of the replacing metalliccations, cations of metals such as rare earth, Mn, Ca, Mg, Zn, Cd, Pt,Pd, Ni, Co, Ti, Al, Sn, Fe and Co are particularly preferred.

The hydrogen, ammonium, and metal components can be exchanged into thezeolite. The zeolite can also be impregnated with the metals, or, themetals can be physically intimately admixed with the zeolite usingstandard methods known to the art. And, the metals can be occluded inthe crystal lattice by having the desired metals present as ions in thereaction mixture from which the SSZ-24 zeolite is prepared.

Typical ion exchange techniques involve contacting the synthetic zeolitewith a solution containing a salt of the desired replacing cation orcations. Although a wide variety of salts can be employed, chlorides andother halides, nitrates, and sulfates are particularly preferred.Representative ion exchange techniques are disclosed in a wide varietyof patents including U.S. Pat. Nos. 3,140,249; 3,140,251; and 3,140,253.Ion exchange can take place either before or after the zeolite iscalcined.

Following contact with the salt solution of the desired replacingcation, the zeolite is typically washed with water and dried attemperatures ranging from 65° C. to about 315° C. After washing, thezeolite can be calcined in air or inert gas at temperatures ranging fromabout 200° C. to 820° C. for periods of time ranging from 1 to 48 hours,or more, to produce a catalytically active product especially useful inhydrocarbon conversion processes.

Regardless of the cations present in the synthesized form of thezeolite, the spatial arrangement of the atoms which form the basiccrystal lattice of the zeolite remains essentially unchanged. Theexchange of cations has little, if any, effect on the zeolite latticestructures.

The SSZ-24 aluminosilicate can be formed into a wide variety of physicalshapes. Generally speaking, the zeolite can be in the form of a powder,a granule, or a molded product, such as extrudate having particle sizesufficient to pass through a 2-mesh (Tyler) screen and be retained on a400-mesh (Tyler) screen. In cases where the catalyst is molded, such asby extrusion with an organic binder, the aluminosilicate can be extrudedbefore drying, or, dried or partially dried and then extruded. Thezeolite can be composited with other materials resistant to thetemperatures and other conditions employed in organic conversionprocesses. Such matrix materials include active and inactive materialsand synthetic or naturally occurring zeolites as well as inorganicmaterials such as clays, silica and metal oxides. The latter may occurnaturally or may be in the form of gelatinous precipitates, sols, orgels, including mixtures of silica and metal oxides. Use of an activematerial in conjunction with the synthetic zeolite, i.e., combined withit, tends to improve the conversion and selectivity of the catalyst incertain organic conversion processes. Inactive materials can suitablyserve as diluents to control the amount of conversion in a given processso that products can be obtained economically without using other meansfor controlling the rate of reaction. Frequently, zeolite materials havebeen incorporated into naturally occurring clays, e.g., bentonite andkaolin. These materials, i.e., clays, oxides, etc., function, in part,as binders for the catalyst. It is desirable to provide a catalysthaving good crush strength, because in petroleum refining the catalystis often subjected to rough handling. This tends to break the catalystdown into powders which cause problems in processing.

Naturally occurring clays which can be composited with the syntheticzeolites of this invention include the montmorillonite and kaolinfamilies, which families include the sub-bentonites and the kaolinscommonly known as Dixie, McNamee, Georgia and Florida clays or others inwhich the main mineral constituent is halloysite, kaolinite, dickite,nacrite, or anauxite. Fibrous clays such as sepiolite and attapulgitecan also be used as supports. Such clays can be used in the raw state asoriginally mined or can be initially subjected to calcination, acidtreatment or chemical modification.

In addition to the foregoing materials, the SSZ-24 zeolites can becomposited with porous matrix materials and mixtures of matrix materialssuch as silica, alumina, titania, magnesia, silica:alumina,silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia,silica-titania, titania-zirconia as well as ternary compositions such assilica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesiaand silica-magnesia-zirconia. The matrix can be in the form of a cogel.

The SSZ-24 zeolites can also be composited with other zeolites such assynthetic and natural faujasites (e.g., X and Y), erionites, andmordenites. They can also be composited with purely synthetic zeolitessuch as those of the ZSM series. The combination of zeolites can also becomposited in a porous inorganic matrix.

SSZ-24 zeolites are useful in hydrocarbon conversion reactions.Hydrocarbon conversion reactions are chemical and catalytic processes inwhich carbon containing compounds are changed to different carboncontaining compounds. Examples of hydrocarbon conversion reactionsinclude catalytic cracking, hydrocracking, and olefin and aromaticsformation reactions. The catalysts are useful in other petroleumrefining and hydrocarbon conversion reactions such as isomerizingn-paraffins and naphthenes, polymerizing and oligomerizing olefinic oracetylenic compounds such as isobutylene and butene-1, reforming,alkylating, isomerizing polyalkyl substituted aromatics (e.g., orthoxylene), and disproportionating aromatics (e.g., toluene) to providemixtures of benzene, xylenes and higher methylbenzenes. The SSZ-24catalysts have high selectivity, and under hydrocarbon conversionconditions can provide a high percentage of desired products relative tototal products.

SSZ-24 zeolites can be used in processing hydrocarbonaceous feedstocks.Hydrocarbonaceous feedstocks contain carbon compounds and can be frommany different sources, such as virgin petroleum fractions, recyclepetroleum fractions, shale oil, liquefied coal, tar sand oil, and, ingeneral, can be any carbon containing fluid susceptible to zeoliticcatalytic reactions. Depending on the type of processing thehydrocarbonaceous feed is to undergo, the feed can contain metal or befree of metals, it can also have high or low nitrogen or sulfurimpurities. It can be appreciated, however, that in general processingwill be more efficient (and the catalyst more active) the lower themetal, nitrogen, and sulfur content of the feedstock.

Using SSZ-24 catalyst which contains a hydrogenation promoter, heavypetroleum residual feedstocks, cyclic stocks and other hydrocrackatecharge stocks can be hydrocracked at hydrocracking conditions includinga temperature in the range of from 175° C. to 485° C., molar ratios ofhydrogen to hydrocarbon charge from 1 to 100, a pressure in the range offrom 0.5 to 350 bar, and a liquid hourly space velocity (LHSV) in therange of from 0.1 to 30.

The hydrocracking catalysts contain an effective amount of at least onehydrogenation catalyst (component) of the type commonly employed inhydrocracking catalysts. The hydrogenation component is generallyselected from the group of hydrogenation catalysts consisting of one ormore metals of Group VIB and Group VIII, including the salts, complexesand solutions containing such. The hydrogenation catalyst is preferablyselected from the group of metals, salts and complexes thereof of thegroup consisting of at least one of platinum, palladium, rhodium,iridium and mixtures thereof or the group consisting of at least one ofnickel, molybdenum, cobalt, tungsten, titanium, chromium and mixturesthereof. Reference to the catalytically active metal or metals isintended to encompass such metal or metals in the elemental state or insome form such as an oxide, sulfide, halide, carboxylate and the like.

The hydrogenation catalyst is present in an effective amount to providethe hydrogenation function of the hydrocracking catalyst, and preferablyin the range of from 0.05 to 25% by weight.

The catalyst may be employed in conjunction with traditionalhydrocracking catalysts, e.g., any aluminosilicate heretofore employedas a component in hydrocracking catalysts. Representative of thezeolitic aluminosilicates disclosed heretofore as employable ascomponent parts of hydrocracking catalysts are Zeolite Y (includingsteam stabilized, e.g., ultra-stable Y), Zeolite X, Zeolite beta (U.S.Pat. No. 3,308,069), Zeolite ZK-20 (U.S. Pat. No. 3,445,727), ZeoliteZSM-3 (U.S. Pat. No. 3,415,736), faujasite, LZ-10 (U.K. Pat. No.2,014,970, June 9, 1982), ZSM-5-type zeolites, e.g., ZSM-5, ZSM-11,ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48, crystalline silicates such assilicalite (U.S. Pat. No. 4,061,724), erionite, mordenite, offretite,chabazite, FU-1-type zeolite, NU-type zeolites, LZ-210-type zeolite andmixtures thereof. Traditional cracking catalysts containing amounts ofNa₂ O less than about one percent by weight are generally preferred. Therelative amounts of the SSZ-24 component and traditional hydrocrackingcomponent, if any, will depend at least in part, on the selectedhydrocarbon feedstock and on the desired product distribution to beobtained therefrom, but in all instances an effective amount of SSZ-24is employed. When a traditional hydrocracking catalyst (THC) componentis employed the relative weight ratio of the THC to the SSZ-24 isgenerally between about 1:10 and about 500:1, desirably between about1:10 and about 200:1, preferably between about 1:2 and about 50:1, andmost preferably is between about 1:1 and about 20:1.

The hydrocracking catalysts are typically employed with an inorganicoxide matrix component which may be any of the inorganic oxide matrixcomponents which have been employed heretofore in the formulation ofhydrocracking catalysts including: amorphous catalytic inorganic oxides,e.g., catalytically active silica-aluminas, clays, silicas, aluminas,silica-aluminas, silica-zirconias, silica-magnesias, alumina-borias,alumina-titanias and the like and mixtures thereof. The traditionalhydrocracking catalyst and SSZ-24 may be mixed separately with thematrix component and then mixed or the THC component and SSZ-24 may bemixed and then formed with the matrix component.

SSZ-24 can be used to convert light straight run naphthas and similarmixtures to highly aromatic mixtures. Thus, normal and slightly branchedchained hydrocarbons, preferably having a boiling range above about 40°C. and less than about 200° C., can be converted to products having asubstantial aromatics content by contacting the hydrocarbon feed withthe zeolite at a temperature in the range of from about 400° C. to 600°C., preferably 480° C.-550° C. at pressures ranging from atmospheric to10 bar, and liquid hourly space velocities (LHSV) ranging from 0.1 to15.

The conversion catalyst preferably contain a Group VIII metal compoundto have sufficient activity for commercial use. By Group VIII metalcompound as used herein is meant the metal itself or a compound thereof.The Group VIII noble metals and their compounds, platinum, palladium,and iridium, or combinations thereof can be used. The most preferredmetal is platinum. The amount of Group VIII metal present in theconversion catalyst should be within the normal range of use inreforming catalysts, from about 0.05 to 2.0 weight percent, preferably0.2 to 0.8 weight percent.

The zeolite/Group VIII metal conversion catalyst can be used without abinder or matrix. The preferred inorganic matrix, where one is used, isa silica-based binder such as Cab-O-Sil or Ludox. Other matrices such asmagnesia and titania can be used. The preferred inorganic matrix isnonacidic.

It is critical to the selective production of aromatics in usefulquantities that the conversion catalyst be substantially free ofacidity, for example by poisoning the zeolite with a basic metal, e.g.,alkali metal, compound. The zeolite is usually prepared from mixturescontaining alkali metal hydroxides and thus have alkali metal contentsof about 1-2 weight percent. These high levels of alkali metal, usuallysodium or potassium, are unacceptable for most catalytic applicationsbecause they greatly deactivate the catalyst for cracking reactions.Usually, the alkali metal is removed to low levels by ion-exchange withhydrogen or ammonium ions. By alkali metal compound as used herein ismeant elemental or ionic alkali metals or their basic compounds.Surprisingly, unless the zeolite itself is substantially free ofacidity, the basic compound is required in the present process to directthe synthetic reactions to aromatics production.

The amount of alkali metal necessary to render the zeolite substantiallyfree of acidity can be calculated using standard techniques based on thealuminum content of the zeolite. Under normal circumstances, the zeoliteas prepared and without ion-exchange will contain sufficient alkalimetal to neutralize the acidity of the catalyst. If a zeolite free ofalkali metal is the starting material, alkali metal ions can be ionexchanged into the zeolite to substantially eliminate the acidity of thezeolite. An alkali metal content of about 100%, or greater, of the acidsites calculated on a molar basis is sufficient.

Where the basic metal content is less than 100% of the acid sites on amolar basis, the test described in U.S. Pat. No. 4,347,394 which patentis incorporated totally herein by reference, can be used to determine ifthe zeolite is substantially free of acidity.

The preferred alkali metals are sodium and potassium. The zeolite itselfcan be substantially free of acidity only at very high silica:aluminamol ratios; by "zeolite consisting essentially of silica" is means azeolite which is substantially free of acidity without base poisoning.

The conversion of hydrocarbonaceous feeds can take place in anyconvenient mode, for example, in fluidized bed, moving bed, or fixed bedreactors depending on the types of process desired. The formulation ofthe catalyst particles will vary depending on the conversion process andmethod of operation.

Other reactions which can be performed using the catalyst of thisinvention containing a metal, e.g., platinum, includehydrogenation-dehydrogenation reactions, denitrogenation anddesulfurization reactions.

SSZ-24 can be used in hydrocarbon conversion reactions with active orinactive supports, with organic or inorganic binders, and with andwithout added metals. These reactions are well known to the art, as arethe reaction conditions.

SSZ-24 can also be used as an adsorbent, as a filler in paper, paint,and toothpastes, and as a water-softening agent in detergents.

The following examples illustrate the preparation of SSZ-24.

EXAMPLES EXAMPLE 1

Preparation of N,N,N-Trimethyl-1-adamantanammonium

Hydroxide (Template A)

Ten (10) grams of 1-adamantanamine (Aldrich) was dissolved in a mixtureof 29 gms tributylamine and 60 mls dimethylformamide. The mixture waschilled in an ice bath.

28.4 Grams of methyl iodide were added dropwise to the chilled solutionwith continuous stirring. After several hours crystals appear. Thereaction was continued overnight and allowed to come to roomtemperature. The crystals were filtered and washed with tetrahydrofuranand then diethyl ether before vacuum drying. Additional product wasobtained by adding enough diethyl ether to the reaction filtrate toproduce two phases and then with vigorous stirring acetone was addeduntil the solution just became one phase. Continued stirring producedcrystallization at which time the solution can be chilled to inducefurther crystallization. The product has a melting point near 300° C.(decomp.) and the elemental analyses and NMR are consistent with theknown structure. The vacuum-dried iodide salt was then ion-exchangedwith ion-exchange resin AG 1×8 (in molar excess) to the hydroxide form.The exchange was performed over a column or more preferably by overnightstirring of the resin beads and the iodide salt in an aqueous solutiondesigned to give about a 0.5 molar solution of the organic hydroxide.This produces Template A.

EXAMPLE 2

A reaction solution was formed from mixing the following reagents. 0.13Grams of KOH(s) was dissolved in 11.6 ml H₂ O containing an additional4.2 gms of Template A (0.71 M) solution. 1.20 gms of Cabosil M5 wasadded with stirring. A pea-shaped teflon-coated stir bar was used andkept in the vessel during reaction. The synthetic reaction was carriedout in a Parr 4745 reactor at 160° C. for 6 days. The reactor wasmounted onto a spit in a Blue M oven and rotated at 30 RPM. Aftercooling the reactor, the contents were poured into a filter and washedrepeatedly with distilled water. After drying the sample in air and thenat 100° C., the product was examined by X-ray diffraction (XRD) andfound to be zeolite SSZ-24. The X-ray diffraction pattern for thisproduct is given in Table 2 below.

                  TABLE 2                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        7.50           11.79   98                                                     13.00          6.81    10                                                     15.00          5.91    46                                                     19.91          4.46    100                                                    21.42          4.15    36                                                     22.64          3.93    87                                                     25.13          3.54     4                                                     26.16          3.41    44                                                     29.37          3.04    13                                                     30.31          2.949   30                                                     34.07          2.631    5                                                     34.86          2.574   20                                                     37.41          2.404    4                                                     38.29          2.351    7                                                     ______________________________________                                    

The x-ray diffraction pattern for SSZ-24 and AlPO-5 are essentially thesame. Unit cell parameters for SSZ-24 and AlPO-5 are given below inTable 3.

                  TABLE 3                                                         ______________________________________                                                        SSZ-24     SSZ-24                                             AlPO-5          As Prepared                                                                              Calcined                                           ______________________________________                                        a =    13.726       13.62      13.62                                          c =     8.484       8.296      8.324                                          ______________________________________                                    

EXAMPLE 3

A reaction was set up as in Example 2. But in this instance, seeds ofthe product of Example 2 were added and the reaction was carried out asbefore but without agitation. The product upon analogous workup andanalysis was about 80% SSZ-24 with the remainder being a layered silicarelated to Kenyaiite and a small quantity of zeolite SSZ-23.

EXAMPLE 4

In this example aluminum was incorporated into the framework of thezeolite. A reaction mixture was put together as in Example 2. This time0.06 gms of Al₂ (SO4)₃ * 18 H₂ O was also added to the reaction. Carewas taken to obtain good dispersion of the aluminum upon mixing so thataluminum-rich gradients are minimized. The SiO₂ /Al₂ O₃ ratio in thesynthesis mixture was 200. The crystalline products obtained fromcarrying out the reaction as in Example 2 are SSZ-24 (major component)and the Kenyaiite-like phase (minor component).

EXAMPLE 5

The crystalline products of Examples 2 and 4 were subjected tocalcination as follows. The samples were heated in a muffle furnace fromroom temperature up to 540° C. at a steadily increasing rate over a7-hour period. The samples were maintained at 540° C. for four morehours and then taken up to 600° C. for an additional four hours. A 50/50mixture of air and nitrogen was passed over the zeolite at a rate of 20standard cubic feet per minute during heating. The calcined product ofExample 2 had the x-ray diffraction lines indicated in Table 4 below.

                  TABLE 4                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        7.50           11.79   100                                                    12.98          6.82    18                                                     15.00          5.91     9                                                     19.89          4.46    34                                                     21.35          4.16    14                                                     22.60          3.93    36                                                     25.08          3.55     1                                                     26.13          3.41    20                                                     29.32          3.05     6                                                     30.27          2.953   23                                                     34.00          2.637    2                                                     34.82          2.576   10                                                     37.35          2.408    2                                                     38.21          2.355    3                                                     ______________________________________                                    

EXAMPLE 6

Ion-exchange of the calcined materials from Example 5 was carried outusing NH₄ NO₃ to convert the zeolites from its K form to NH4 and theneventually H form. Typically the same mass of NH₄ NO₃ as zeolite wasslurried into H₂ O at ratio of 50/l H₂ O to zeolite. The exchangesolution was heated at 100° C. for two hours and then filtered. Thisprocess was repeated four times. Finally, after the last exchange thezeolite was washed several times with H₂ O and dried. A repeatcalcination as in Example 5 was carried out but without the finaltreatment at 600° C. This produces the H form of the zeolites. Thesurface area for this material was 300 m² /gm. The micro pore volume was0.12 cc/gm as determined by BET method with N₂ as absorbate.

EXAMPLE 7 Constraint Index Determination

0.25 Grams of the hydrogen form of the zeolite of Example 4 (aftertreatment according to Examples 5 and 6) was packed into a 3/8"stainless steel tube with alundum on both sides of the zeolite bed. ALindburg furnace was used to heat the reactor tube. Helium wasintroduced into the reactor tube at 10cc/min. and atmospheric pressure.The reactor was taken to 250° F. for 40 min. and then raised to 800° F.Once temperature equilibration was achieved a 50/50, w/w feed ofn-hexane and 3-methylpentane was introduced into the reactor at a rateof 0.62 cc/hr. Feed delivery was made via syringe pump. Direct samplingonto a gas chromatograph begun after 10 minutes of feed introduction.Constraint Index values were calculated from gas chromatographic datausing methods known in the art.

    ______________________________________                                        Example No.                                                                            C.I.     Conversion at 10 min.                                                                        Temp. °F.                             ______________________________________                                        4        0.5      5%             800                                          ______________________________________                                    

EXAMPLE 8

A catalyst was prepared as in Example 6 and was impregnated with aplatinum tetramine dinitrate solution to give a final platinum loadingof 0.8% Pt. After calcination, the catalyst was screened for reforming.A light paraffinic C₅ -C₇ sraight run stream was run over the catalystunder the following conditions:

    ______________________________________                                                  LSHV  =       6                                                               H.sub.2 /HC                                                                         =       6                                                               PSIG  =       100                                                             Temp. =       920° F.                                        ______________________________________                                    

The catalyst showed 11% conversion of C₆ +C₇ paraffins over severalhours on stream with a 55% selectivity to aromatics and an 89% liquidvolume yiled, indicating that there was very little extraneous cracking.

What is claimed is:
 1. A zeolite having a mole ratio of an oxideselected from silicon oxide, germanium oxide and mixtures thereof to anoxide selected from aluminum oxide, gallium oxide, iron oxide, boronoxide and mixtures thereof greater than about 100:1, and having theX-ray diffraction lines of Table
 1. 2. A zeolite having a composition,as synthesized and in the anhydrous state, in terms of mole ratios ofoxides as follows: (0.1 to 10)Q₂ O:(0.1 to 5.0)M₂ O:W₂ O₃ : (greaterthan 100) YO₂ wherein M is an alkali metal cation, W is selected fromaluminum, gallium, iron, boron and mixtures thereof, Y is selected fromsilicon, germanium and mixtures thereof, Q is an adamantane quaternaryammonium ion and having the X-ray diffraction lines of Table
 1. 3. Thezeolite according to claim 2 wherein W is aluminum and Y is silicon. 4.A zeolite prepared by thermally treating the zeolite of claim 3 at atemperature from about 200° C. to 820° C.
 5. A zeolite according toclaim 2 wherein the adamantane quaternary ammonium ion is derived froman adamantane compound of the formula: ##STR3## wherein each of Y₁ Y₂and Y₃ independently is lower alkyl and A.sup.⊖ is an anion which is notdetrimental to the formation of the zeolite; and each of R₁, R₂ and R₃independently is hydrogen, or lower alkyl; or ##STR4## wherein each ofR₄, R₅ and R₆ independently is hydrogen or lower alkyl; each of Y₁, Y₂and Y₃ independently is lower alkyl; and A.sup.⊖ is an anion which isnot detrimental to the formation of the zeolite.
 6. A zeolite accordingto claim 5 wherein in formula (a) each of Y₁, Y₂ and Y₃ independently ismethyl or ethyl; A.sup.⊖ is OH or halogen; and each of R₁, R₂, and R₃ ishydrogen; and in formula (b) each of Y₁, Y₂ and Y₃ independently ismethyl or ethyl; A.sup.⊖ is OH, or halogen; and each of R₄, R₅ and R₆ ishydrogen.
 7. A zeolite according to claim 6 wherein Y₁, Y₂ and Y₃ arethe same and each is methyl; and A.sup.⊖ is OH, or I.
 8. A zeoliteaccording to claim 1 or 2 which has undergone ion exchange withhydrogen, ammonium, rare earth metal, Group IIA metal, or Group VIIImetal ions.
 9. A zeolite according to claim 1 or 2 wherein rare earthmetals, Group IIA metals, or Group VIII metals are occluded in thezeolite.
 10. A zeolite composition, comprising the zeolite of claim 1 or2 and an inorganic matrix.